This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Studies have continued this year assessing the consequences of psychosocial stress, resulting from social subordination, on metabolic, reproductive, and behavioral outcomes I adult female rhesus monkeys. In addition, the contribution of polymorphisms in the gene that encodes the serotonin reuptake transporter (5HTT) was evaluated as other studies show individuals carrying one or both alleles of the short promoter length variant (s-variant) are more vulnerable to the adverse consequences of psychosocial stress than females homozygous for the long promoter length (l/l). During the current year, the effects of estradiol and progesterone on metabolic hormones and anthropometric measures were evaluated. Estradiol significantly reduced body weights and fat in all females, regardless of social status and genotype and this effect was reversed by progesterone. Serum leptin levels paralleled changes in body weight. A second study evaluated the hypothesis that administration of a corticotropin releasing hormone (CRH) receptor analogue would decrease LH secretion, particularly in subordinate animals. Females received estradiol alone or in combination with a CRH receptor analogue. Subordinate females, particularly those with the s-variant 5HTT genotype, were hypersensitive to the negative feedback action of estradiol on LH. Co-administration of the CRH receptor analogue enhanced estradiol negative feedback in all females, and even to a greater degree in subordinate females. These studies provide insights into possible treatment strategies for women suffering from stress-induced infertility.